Steve Arms '81, G'84 and the many UVM alumni on his team. (Photo: Alison Redlich)

His business began with rats. More specifically, rats' knees.

It was 1978, and UVM sophomore Steve Arms had landed a good work-study job in the department of orthopedics and rehabilitation. "I'd take dead lab rats and prepare a specimen that was just the medial collateral ligament and the bones on either end," says Arms, president and founder of MicroStrain, Inc., pointing his two index fingers together like a joint.

In the lab of Dr. Robert Johnson, Arms would load the specimen into a machine that would repeatedly flex the knee. "We were trying to figure out how the ligament was affected by cyclic loading. There was interest in the idea that ski injuries could be prevented this way," he says.

Arms began to ask Johnson basic questions, like: "How do you know what strain level to set this machine to? What are the strains when people ski or walk?" he says, smiling broadly at the recollection, "I was a curious kid."

"And the answer came back, 'Well, we don't really know!'" he says. "So I asked: how come you don't know? 'Because we don't know how to measure it.'"

Arms decided to look for a solution. Over the next few years, he developed an innovative device to measure strain — "a tube with a magnetic sensor and teeny magnet," he says — that became the first strain gauges ever implanted in the knee ligaments of a living human.

Since then, Arms, '81 G '84, and his company have gotten extraordinarily good at measuring motion: in 2003, when the Liberty Bell needed to be moved, the National Park Service called in MicroStrain to detect whether the bell's famed crack was widening by even a hundredth of a hair's width.

It wasn't. But the company's business has expanded beyond miniature strain gauges. In a conference room of his 19,000-square-foot manufacturing facility, Arms picks up a black plastic wafer about the size of a Lego. "In here are three gyroscopes, three magnetometers, and three accelerometers, on three axes — and a processor that reads all that," he says, holding it aloft near one of the equation-covered white boards that line the walls.

"It knows its pitch, roll, and yaw," he says and then slides it downward through the air like a toy plane, "and it knows how fast you accelerated. Combine that with some more math, and you can get a good estimate of location."

Which can help rescuers find a downed firefighter in a burning building, or guide an unmanned aircraft, or help an oil company map a hole two miles deep.

"Just one? About $1,400. If you want thousands, the price comes down," he says.

Answering basic questions about how to measure movement, location, and force — in ever-smaller devices, harsher conditions, and with less power — has propelled Arms from a one-man business in his graduate student apartment on Park Street in Burlington, to a fifty-person company in Williston with $10 million in annual revenue.

"Our business is constantly innovating, so it's really important to be near a university," he says. "We hire lots of UVM students who have worked here as interns. Vermonters are very self-motivated."

Today, MicroStrain builds a range of "microminiature" devices like wearable medical dataloggers, and thumbnail-length sensors that work in boiling hot oil or that wirelessly broadcast structural damage within a bridge.

"We've grown 30 to 40 percent every year for the last five years," he says, "and a major reason for our success is that we take the time to find out what our customers' problems are and what they really want."

"Like this," he says, and points to a helicopter mast, whipping around in his company's test lab. It's part of a contract MicroStrain made with the Navy to build a wireless system to monitor wear on rotating parts in helicopters—and that uses energy harvested from the helipcopter's own motion to power the sensors.

"One of my big areas of interest now is cyclic loading on metals and fatigue of mechanical parts, like these helicopter components," Arms says, "My path has led me back to what I started doing with those rat knee specimens a long time ago."

This article originally appeared in the recently published issue of Vermont Quarterly magazine as one section of a larger piece on UVM alumni who are helping to grow Vermont's economic landscape. The fall 2009 issue is online at alumni.uvm.edu/vq, and print copies are available from University Communications, 656-2005.